As a result of their physical properties, partially esterified polyol fatty acid polyesters are commonly used as emulsifiers and surfactants in various food, beverage, and cosmetic compositions. There exists in the art various techniques for the synthesis of these partially esterified polyol fatty acid polyesters.
U.S. Pat. No. 4,927,920, to Wagner et al. discloses a process for the production of sugar esters with a degree of substitution of less than two by reacting a sugar, an organic solvent, and a sugar ester with a degree of substitution greater than two. The recovery of the solvent occurs at a temperature below the distillation temperature of the organic solvent.
U.S. Pat. No. 4,996,309, to Matsumoto et al. discloses a process for preparing sucrose fatty acid esters by reacting sucrose and fatty acid alkyl esters in the presence of a catalyst. The resulting sucrose esters are collected and washed with an acid solution.
Although conventional processes for the manufacture of partially esterified polyol fatty acid polyesters have known utilities, they suffer from several deficiencies, most notable of which are poor reaction control and the need for expensive, complex and continuous purification techniques. Additionally, these known processes are unable to accurately predict and consistently control the exact composition of the finished product without the use of complex sampling and control modification procedures throughout the reaction.
These known processes also suffer from an inability to accurately control the average degree of esterification in the final partially esterified polyol polyester compositions. Moreover, the partially esterified polyol polyester compositions produced from these known synthesis techniques typically contain unacceptable levels of impurities, such as solvent, polyol, lower alkyl esters, ash, soap, free fatty acids, and other unwanted reaction byproducts.
These limitations have heretofore constrained the industrial applicability and cost effective commercialization of these compounds in various food, beverage, pharmaceutical, and cosmetic applications.
Accordingly, it is an object of the present invention to provide processes for the synthesis of purified, partially esterified polyol polyesters that allow for the production of polyol polyesters with the degree of purity necessary for widespread incorporation into a variety of industrial and commercial applications. It is another object of the present invention to provide purified, partially esterified polyol polyester compositions with a degree of purity sufficient to be used in a variety of industrial and commercial applications. It is yet another object of the present invention to provide processes for the production of purified polyol polyesters that are efficient, cost effective, and require less purification than those now known and employed in the art.